In recent years there has been a penetration of consumer and professional GNSS (Global Navigation Satellite System) technologies into the same markets. Consumer-grade devices are seeking better accuracy at the lowest price. Professional-grade solutions are seeking price/size/consumption reduction keeping ultimate positioning performance. The battle is on to achieve sub-meter positioning performance for post-processed and real-time GIS (Geographic Information System/s).
Today, GIS handhelds represent a significant GIS market. In terms of accuracy, there is a very wide choice, ranging from a few-meter real-time solutions (low-end GIS) to centimeter-level, post-processed and real-time solutions (high-end GIS).
Typical high-end GIS players are Trimble GeoExplorer 6000 Series, Topcon GRS-1, and Ashtech MobileMapper 100. All of them include their own professional GNSS inside (usually GPS+GLONASS, L1 or L1&L2), good quality internal antenna (usually L1-only; sometimes L1&L2), the possibility to connect high-grade, external L1 or L1&L2 antenna, built-in GSM module & antenna, possibility to support high-rate raw data output for post-processing, and the RTK rover function.
Having such a device, end users can get a full spectrum of accuracies (from meter up to centimeter) by selecting the proper antenna, recording raw data and running post-processing at the office or activating the RTK function, etc.
But these are expensive devices ($3000+ depending on options), which makes them suitable only for some applications and circumstances.
All of the low-end GIS devices use consumer-grade L1 GPS (and SBAS) chips. Here the obvious leader is the SiRF Star III chip. Typical low-end GIS players are Topcon FC-25A, Ashtech MobileMapper 10, Spectra Precision Nomad, Trimble Juno series, Magellan eXplorist Pro 10 and some others. All of them deliver a few meter-level, real-time accuracy using an internal SiRF chip (i.e. 3rd party consumer GPS) as search&tracking&position engine. This means that the difference in real-time performance between units is only defined by the difference of quality in the design of the internal antenna.
These are quite inexpensive units ($400+ depending on options), which can be used in the widest range of GIS applications all over the world.
Thus, there is a strong differentiation between low-end and high-end GIS solutions as for the accuracy and the price.
At the same time, there exists the so-called medium-end GIS market, which requires meter-level, real-time and sub-meter level post-processing accuracies.
This niche can potentially be occupied by both low- and high-end devices. It is quite clear what needs to be done when moving from high- to medium-end: Reducing the price! It is clear but not so easy to do because pricing for professional solutions is also driven by capabilities other than GNSS positioning (e.g. data capacity, ruggedness, connectivity, etc).
There are lots of consumer-grade handheld devices available on the market. Generally they are fitted with a consumer GNSS chipset (e.g. SiRF, Ublox, etc.), a low-cost internal antenna element and a powerful application processor to run different user applications. More and more of these devices have large touch screens, built-in GSM modules and the possibility to connect a higher grade, external GNSS antenna. Such a configuration is ideal for a wide variety of GIS jobs. What needs to be improved in these devices is just the chip performance to deliver an accurate enough (differential) position!
To date, we do not see consumer-grade devices with such an advanced position engine. Today, the primary market for such chips is still PNDs (Portable Navigation Devices) where sub-ten meter position is usually enough for most applications. Improving position accuracy is not required, while ultra-high sensitivity, indoor tracking with minimum size and power consumption and low cost are still the primary requirements for such chips.